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Method and apparatus for decoding two-dimensional bar code

Assignee: Symbol Technologies LLC
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Filing: 1994-06-03
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Granted: 1997-06-03
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Expires: 2014-06-03
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Abstract

Abstract A method and apparatus for decoding a two-dimensional bar code symbol using a charge-coupled device (CCD) camera, charge-modulation device (CMD) camera, or other bar code reading device such as a hand-held reader, light pen or wand, scan mouse, or stationary laser scanner. The CCD/CMD camera or reading device optically images the bar code symbol to obtain digital image data, which is stored in a memory. The location and orientation of the two-dimensional bar code

Inventors

  • 👤 Stephen J. Shellhammer
  • 👤 Arman Nikzad
  • 👤 Jerome Swartz

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 15:00
CPC Classifications
G; G06; G06K; G06K7/00; G06K7/10; G06K7/10544; G06K7/10821; G06K7/1093; G06F; G06F3/00; G06F3/002; G06K1/00; G06K1/12; G06K1/126; G06K19/00; G06K19/06; G06K19/06009; G06K19/06037; G06K7/01; G06K7/016; G06K7/0166; G06K7/10712; G06K7/10722; G06K7/14; G06K7/1404; G06K7/1408; G06K7/1417; G06K7/1439; G06K7/1443; G06K7/1456; G06K2019/06215; G06K2019/06253

Claims Analysis

Total Claims: 14
Claim 1
Independent Claim 166 words
A system for reading and decoding a two-dimensional bar code symbol having rows of bar-coded information in which data is represented in each row by a plurality of codewords, each row including a predetermined control codeword, the codewords being formed of a plurality of modules, comprising: a two-dimensional imaging camera for optically imaging the bar code symbol to obtain lines of image data corresponding to a field of view including the bar code symbol; a memory for storing the lines of image data; means for determining an orientation of the two-dimensional bar code symbol in the field of view by locating control codewords in at least two positions in the image data; means for determining a sequence of lines passing through the rows of the bar code symbol in the image data from the orientation determined from the positions of the control codewords; and means for scanning the two-dimensional bar code symbol in the image data along the sequence of lines line to read the codewords.
Claim 2
Independent Claim 166 words
A system for reading and decoding a two-dimensional bar code symbol having rows of bar-coded information in which data is represented in each row by a plurality of codewords, each row including a predetermined control codeword, the codewords being formed of a plurality of modules, comprising: a two-dimensional imaging camera for optically imaging the bar code symbol to obtain lines of image data corresponding to a field of view including the bar code symbol; a memory for storing the lines of image data; means for determining an orientation of the two-dimensional bar code symbol in the field of view by locating control codewords in at least two positions in the image data; means for determining a sequence of lines passing through the rows of the bar code symbol in the image data from the orientation determined from the positions of the control codewords; and means for scanning the two-dimensional bar code symbol in the image data along the sequence of lines line to read the codewords.
Claim 3
Dependent Claim 46 words
The system according to claim 1, wherein each row of the symbol includes two predetermined control codewords, one control codeword being a start codeword at the beginning of each row and the other control codeword being a stop control codeword at the end of each row.
Claim 4
Dependent Claim 29 words
The system according to claim 1, further comprising means for detecting defects in the two-dimensional bar code symbol and correcting the detected defects in the two-dimensional bar code symbol.
Claim 5
Dependent Claim 27 words
The system according to claim 1, further comprising a host computer for decoding the codewords obtained by scanning the two-dimensional bar code symbol in the image data.
Claim 6
Dependent Claim 21 words
The system according to claim 1, further comprising a frame grabber for converting analog signals from the camera into digital signals.
Claim 7
Dependent Claim 21 words
The system according to claim 1, wherein the bar code symbol contains a plurality of modes in which data is stored.
Claim 8
Independent Claim 172 words
A method for reading and decoding a two-dimensional bar code symbol having rows of bar-coded information in which data is represented in each row by a plurality of codewords, each row including a predetermined control codeword which is the same for each row, the codewords being formed of a plurality of modules, the method comprising the steps of: optically imaging the two-dimensional bar code symbol using a two-dimensional imaging camera to obtain lines of image data corresponding to a field of view including the bar code symbol; storing the lines of image data in a memory; determining an orientation of the two-dimensional bar code symbol in the field of view by locating control codewords in at least two positions in the image data; determining a sequence of lines passing through the rows of the bar code symbol in the image data from the orientation derived from the positions of the control codewords; and scanning the two-dimensional bar code symbol in the image data along the sequence of lines to read the codewords.
Claim 9
Independent Claim 172 words
A method for reading and decoding a two-dimensional bar code symbol having rows of bar-coded information in which data is represented in each row by a plurality of codewords, each row including a predetermined control codeword which is the same for each row, the codewords being formed of a plurality of modules, the method comprising the steps of: optically imaging the two-dimensional bar code symbol using a two-dimensional imaging camera to obtain lines of image data corresponding to a field of view including the bar code symbol; storing the lines of image data in a memory; determining an orientation of the two-dimensional bar code symbol in the field of view by locating control codewords in at least two positions in the image data; determining a sequence of lines passing through the rows of the bar code symbol in the image data from the orientation derived from the positions of the control codewords; and scanning the two-dimensional bar code symbol in the image data along the sequence of lines to read the codewords.
Claim 10
Dependent Claim 46 words
The method according to claim 7, wherein each row of the symbol includes two predetermined control codewords, one control codeword being a start codeword at the beginning of each row and the other control codeword being a stop control codeword at the end of each row.
Claim 11
Dependent Claim 31 words
The method according to claim 7, further comprising the steps of detecting defects in the two-dimensional bar code symbol; and scanning the two-dimensional bar code symbol despite the presence of defects.
Claim 12
Dependent Claim 30 words
The method according to claim 7, further comprising the step of decoding in a host computer the codewords obtained by scanning the two-dimensional bar code symbol in the image data.
Claim 13
Dependent Claim 24 words
The method according to claim 7, further comprising the step of converting analog signals from the camera into digital signals using a frame grabber.
Claim 14
Dependent Claim 21 words
The method according to claim 7, wherein the bar code symbol contains a plurality of modes in which data is stored.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2000-06-02 2000-12-02 2001-06-03 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2004-06-02 2004-12-02 2005-06-03 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2008-06-02 2008-12-02 2009-06-03 $7700.00 Window Closed / Lapsed

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